Oxygen and strontiumisotopes, which are fixed in dental enamel at the time of tooth formation, were tested in 18 subjects.
在18件样本上检测了氧和锶的同位素。这两种元素在牙齿成型时，会固定在牙釉质上。
2
The Mesozoic and the Cenozoic are geological periods in which the greatest change in the composition of seawater strontiumisotopes occurred.
中新生代是地质历史中海水锶同位素组成变化最大的时期。
3
This is because particular isotopes of strontium dominant within a geological region are digested by individuals living there and incorporated into their tooth enamel.